From f40190a6a541479e504d783cd984670c6fa6cb39 Mon Sep 17 00:00:00 2001 From: David Laban Date: Mon, 5 Aug 2019 15:26:08 +0100 Subject: [PATCH] test drop order for parameters when a future is dropped part-way through execution --- .../drop-order/drop-order-when-cancelled.rs | 307 ++++++++++++++++++ 1 file changed, 307 insertions(+) create mode 100644 src/test/ui/async-await/drop-order/drop-order-when-cancelled.rs diff --git a/src/test/ui/async-await/drop-order/drop-order-when-cancelled.rs b/src/test/ui/async-await/drop-order/drop-order-when-cancelled.rs new file mode 100644 index 0000000000000..21600cfc139b2 --- /dev/null +++ b/src/test/ui/async-await/drop-order/drop-order-when-cancelled.rs @@ -0,0 +1,307 @@ +// aux-build:arc_wake.rs +// edition:2018 +// run-pass + +#![allow(unused_variables)] +#![feature(async_await)] + +// Test that the drop order for parameters in a fn and async fn matches up. Also test that +// parameters (used or unused) are not dropped until the async fn is cancelled. +// This file is mostly copy-pasted from drop-order-for-async-fn-parameters.rs + +extern crate arc_wake; + +use arc_wake::ArcWake; +use std::cell::RefCell; +use std::future::Future; +use std::marker::PhantomData; +use std::pin::Pin; +use std::rc::Rc; +use std::sync::Arc; +use std::task::{Context, Poll}; + +struct EmptyWaker; + +impl ArcWake for EmptyWaker { + fn wake(self: Arc) {} +} + +#[derive(Debug, Eq, PartialEq)] +enum DropOrder { + Function, + Val(&'static str), +} + +type DropOrderListPtr = Rc>>; + +struct D(&'static str, DropOrderListPtr); + +impl Drop for D { + fn drop(&mut self) { + self.1.borrow_mut().push(DropOrder::Val(self.0)); + } +} + +struct NeverReady; + +impl Future for NeverReady { + type Output = (); + fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll { + Poll::Pending + } +} + +/// Check that unused bindings are dropped after the function is polled. +async fn foo_async(x: D, _y: D) { + x.1.borrow_mut().push(DropOrder::Function); + NeverReady.await; +} + +fn foo_sync(x: D, _y: D) { + x.1.borrow_mut().push(DropOrder::Function); +} + +/// Check that underscore patterns are dropped after the function is polled. +async fn bar_async(x: D, _: D) { + x.1.borrow_mut().push(DropOrder::Function); + NeverReady.await; +} + +fn bar_sync(x: D, _: D) { + x.1.borrow_mut().push(DropOrder::Function); +} + +/// Check that underscore patterns within more complex patterns are dropped after the function +/// is polled. +async fn baz_async((x, _): (D, D)) { + x.1.borrow_mut().push(DropOrder::Function); + NeverReady.await; +} + +fn baz_sync((x, _): (D, D)) { + x.1.borrow_mut().push(DropOrder::Function); +} + +/// Check that underscore and unused bindings within and outwith more complex patterns are dropped +/// after the function is polled. +async fn foobar_async(x: D, (a, _, _c): (D, D, D), _: D, _y: D) { + x.1.borrow_mut().push(DropOrder::Function); + NeverReady.await; +} + +fn foobar_sync(x: D, (a, _, _c): (D, D, D), _: D, _y: D) { + x.1.borrow_mut().push(DropOrder::Function); +} + +struct Foo; + +impl Foo { + /// Check that unused bindings are dropped after the method is polled. + async fn foo_async(x: D, _y: D) { + x.1.borrow_mut().push(DropOrder::Function); + NeverReady.await; + } + + fn foo_sync(x: D, _y: D) { + x.1.borrow_mut().push(DropOrder::Function); + } + + /// Check that underscore patterns are dropped after the method is polled. + async fn bar_async(x: D, _: D) { + x.1.borrow_mut().push(DropOrder::Function); + NeverReady.await; + } + + fn bar_sync(x: D, _: D) { + x.1.borrow_mut().push(DropOrder::Function); + } + + /// Check that underscore patterns within more complex patterns are dropped after the method + /// is polled. + async fn baz_async((x, _): (D, D)) { + x.1.borrow_mut().push(DropOrder::Function); + NeverReady.await; + } + + fn baz_sync((x, _): (D, D)) { + x.1.borrow_mut().push(DropOrder::Function); + } + + /// Check that underscore and unused bindings within and outwith more complex patterns are + /// dropped after the method is polled. + async fn foobar_async(x: D, (a, _, _c): (D, D, D), _: D, _y: D) { + x.1.borrow_mut().push(DropOrder::Function); + NeverReady.await; + } + + fn foobar_sync(x: D, (a, _, _c): (D, D, D), _: D, _y: D) { + x.1.borrow_mut().push(DropOrder::Function); + } +} + +struct Bar<'a>(PhantomData<&'a ()>); + +impl<'a> Bar<'a> { + /// Check that unused bindings are dropped after the method with self is polled. + async fn foo_async(&'a self, x: D, _y: D) { + x.1.borrow_mut().push(DropOrder::Function); + NeverReady.await; + } + + fn foo_sync(&'a self, x: D, _y: D) { + x.1.borrow_mut().push(DropOrder::Function); + } + + /// Check that underscore patterns are dropped after the method with self is polled. + async fn bar_async(&'a self, x: D, _: D) { + x.1.borrow_mut().push(DropOrder::Function); + NeverReady.await; + } + + fn bar_sync(&'a self, x: D, _: D) { + x.1.borrow_mut().push(DropOrder::Function); + } + + /// Check that underscore patterns within more complex patterns are dropped after the method + /// with self is polled. + async fn baz_async(&'a self, (x, _): (D, D)) { + x.1.borrow_mut().push(DropOrder::Function); + NeverReady.await; + } + + fn baz_sync(&'a self, (x, _): (D, D)) { + x.1.borrow_mut().push(DropOrder::Function); + } + + /// Check that underscore and unused bindings within and outwith more complex patterns are + /// dropped after the method with self is polled. + async fn foobar_async(&'a self, x: D, (a, _, _c): (D, D, D), _: D, _y: D) { + x.1.borrow_mut().push(DropOrder::Function); + NeverReady.await; + } + + fn foobar_sync(&'a self, x: D, (a, _, _c): (D, D, D), _: D, _y: D) { + x.1.borrow_mut().push(DropOrder::Function); + } +} + +fn assert_drop_order_after_cancel>( + f: impl FnOnce(DropOrderListPtr) -> Fut, + g: impl FnOnce(DropOrderListPtr), +) { + let empty = Arc::new(EmptyWaker); + let waker = ArcWake::into_waker(empty); + let mut cx = Context::from_waker(&waker); + + let actual_order = Rc::new(RefCell::new(Vec::new())); + let mut fut = Box::pin(f(actual_order.clone())); + let _ = fut.as_mut().poll(&mut cx); + + // Parameters are never dropped until the future completes. + assert_eq!(*actual_order.borrow(), vec![DropOrder::Function]); + + drop(fut); + + let expected_order = Rc::new(RefCell::new(Vec::new())); + g(expected_order.clone()); + assert_eq!(*actual_order.borrow(), *expected_order.borrow()); +} + +fn main() { + // Free functions (see doc comment on function for what it tests). + assert_drop_order_after_cancel( + |l| foo_async(D("x", l.clone()), D("_y", l.clone())), + |l| foo_sync(D("x", l.clone()), D("_y", l.clone())), + ); + assert_drop_order_after_cancel( + |l| bar_async(D("x", l.clone()), D("_", l.clone())), + |l| bar_sync(D("x", l.clone()), D("_", l.clone())), + ); + assert_drop_order_after_cancel( + |l| baz_async((D("x", l.clone()), D("_", l.clone()))), + |l| baz_sync((D("x", l.clone()), D("_", l.clone()))), + ); + assert_drop_order_after_cancel( + |l| { + foobar_async( + D("x", l.clone()), + (D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())), + D("_", l.clone()), + D("_y", l.clone()), + ) + }, + |l| { + foobar_sync( + D("x", l.clone()), + (D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())), + D("_", l.clone()), + D("_y", l.clone()), + ) + }, + ); + + // Methods w/out self (see doc comment on function for what it tests). + assert_drop_order_after_cancel( + |l| Foo::foo_async(D("x", l.clone()), D("_y", l.clone())), + |l| Foo::foo_sync(D("x", l.clone()), D("_y", l.clone())), + ); + assert_drop_order_after_cancel( + |l| Foo::bar_async(D("x", l.clone()), D("_", l.clone())), + |l| Foo::bar_sync(D("x", l.clone()), D("_", l.clone())), + ); + assert_drop_order_after_cancel( + |l| Foo::baz_async((D("x", l.clone()), D("_", l.clone()))), + |l| Foo::baz_sync((D("x", l.clone()), D("_", l.clone()))), + ); + assert_drop_order_after_cancel( + |l| { + Foo::foobar_async( + D("x", l.clone()), + (D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())), + D("_", l.clone()), + D("_y", l.clone()), + ) + }, + |l| { + Foo::foobar_sync( + D("x", l.clone()), + (D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())), + D("_", l.clone()), + D("_y", l.clone()), + ) + }, + ); + + // Methods (see doc comment on function for what it tests). + let b = Bar(Default::default()); + assert_drop_order_after_cancel( + |l| b.foo_async(D("x", l.clone()), D("_y", l.clone())), + |l| b.foo_sync(D("x", l.clone()), D("_y", l.clone())), + ); + assert_drop_order_after_cancel( + |l| b.bar_async(D("x", l.clone()), D("_", l.clone())), + |l| b.bar_sync(D("x", l.clone()), D("_", l.clone())), + ); + assert_drop_order_after_cancel( + |l| b.baz_async((D("x", l.clone()), D("_", l.clone()))), + |l| b.baz_sync((D("x", l.clone()), D("_", l.clone()))), + ); + assert_drop_order_after_cancel( + |l| { + b.foobar_async( + D("x", l.clone()), + (D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())), + D("_", l.clone()), + D("_y", l.clone()), + ) + }, + |l| { + b.foobar_sync( + D("x", l.clone()), + (D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())), + D("_", l.clone()), + D("_y", l.clone()), + ) + }, + ); +}